
import React, { useState } from 'react'

export default function App() {
   const [unm , setUnm] = useState(50)
  return (
    <div>

        <h1>体重值{unm}kg</h1>
        <button onClick = {() => { setUnm(unm + 1)}}>点击加一</button>
    </div>
  )
}
